The Harrington rod (or Harrington implant) is a stainless steel surgical device. Historically, this rod was implanted along the spinal column to treat, among other conditions, a lateral or coronal-plane curvature of the spine, or scoliosis. Harrington rod instrumentation was used to treat instability and deformity of the spine. Instability occurs when the spine no longer maintains its normal shape during movement. Such instability results in nerve damage, spinal deformities, and disabling pain. Spinal deformities may be caused by birth defects, fractures, marfan syndrome, neurofibromatosis, neuromuscular diseases, severe injuries, and tumors. By far, the most common use for the Harrington rod was in the treatment of scoliosis, for which it was invented.
Use of pedicle screw systems for spinal stabilization has become increasingly common in spine surgery. Since pedicle screws traverse all three columns of the vertebrae, they can rigidly stabilize both the ventral and dorsal aspects of the spine. The pedicle also represents the strongest point of attachment of the spine and thus significant forces can be applied to the spine without failure of the bone-metal junction. Furthermore, the rigidity of pedicle fixation allows for the incorporation of fewer normal motion segments in order to achieve stabilization of an abnormal level. Pedicle screw fixation does not require intact dorsal elements. Thus, it can be used after a laminectomy or traumatic disruption of laminae, spinous processes and/or facets. Additional advantages include less requirements for postoperative bracing and improvements in fusion rates.